Guidelines for Delivering as One in ict at the Country Level
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| Cooling Hot aisle/cold aisle is an accepted best practice for cabinet layout within a data centre. The design uses air conditioners, fans, and raised floors as a cooling infrastructure and focuses on separation of the inlet cold air and the exhaust hot air. The racks are arranged into a series of rows, resting on a raised floor. The fronts of the racks face each other and become cold aisles, due to the front-to-back heat dissipation of most IT equipment. Air conditioners push cold air under the raised floor and through the cold aisle, Perforated raised floor tiles are placed only in the cold aisles concentrating cool air to the front of racks to get sufficient air to the server intake. As the air moves through the servers, it's heated and eventually dissipated into the hot aisle. The exhaust air is then routed back to the air handlers. On average, 1 ton of cooling is required for each populated rack. So a data centre with 10 racks should have a 10 ton system. Rather than one 10 ton system, to ensure redundancy, three 5 ton units should be used. This way, should one unit fail (which occurs around once a year in a normal operating environment, the remaining units will provide adequate cooling for all equipment. Optimal temperature ranges are C to CF to F. Considering that AC units are difficult and expensive to install, it is recommended that cooling capacity be based not on the current number of populated racks, but on the maximum number of racks projected to occupy the data centre. It is important that cooling units not be too powerful for the data centre, as they will have a tendency to shutoff for extended periods, resulting in high levels of humidity. If a data centre room is too humid, condensation can build on computer components and cause them to short out. In addition, high humidity can cause condensation to form on the coils of a cooling unit, causing it to work harder to rid itself of the condensation, which in turn can lead to wasted cooling, also called latent cooling, and that costs money. Meanwhile, if humidity is too low, data centers can experience electrostatic discharge (ESD), which can shutdown electronic equipment and possibly damage it. Optimal humidity levels are 40% to 60% and it is important that the cooling unit control both temperature and humidity. Having multiple AC units which can be switched on or off depending on the cooling and humidity requires is a good way to address these concerns. ICT Reference Group Guidelines for DaO in ICT at the Country Level Page 51 of 59 If at all possible, the reduction and virtualization of servers will result in a number of significant advantages, with decreased cooling requirements as one of significant importance. Other advantages of virtualization are decreased power, cost, simplified application installation, and decreased space needs. Download 0.67 Mb. Share with your friends:
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